Retailers like Nordstrom, Family Dollar, and Warby Parker are
gathering customer data from smartphones and using video
surveillance to determine optimal store layouts and customized
coupons offerings,
The New York Times reports.

Using Wi-Fi signals from your smartphone, retailers can gain
insights about how much time you spend in the store, which
sections you spend the most time in, and how long it takes you to
browse before making a purchase.

Some people argue that it's a huge invasion of privacy. But
retailers maintain that tracking customers in the physical retail
environment is the same as tracking them online through
cookies.

Finnish startup Walkbase is among several companies aiming to
help retailers learn more about their customers' behavior.

Walkbase tracks every customer with a WLAN-enabled smartphone.
That means any phone with Wi-Fi turned on is subject to tracking,
but all of the data collected is completely anonymous. Users can
also opt-out of being tracked by simply turning off Wi-Fi.

Walkbase provides analytics like capture rate (percentage of
passerbys that actually walk into the store), volume trends
(changes in foot traffic), dwell time (how long they spend inside
the store), repeat versus new customers, and behavior inside the
store.

New York startup Nomi similarly relies on a customer's
smartphone to provide real-time analytics to traditional
retailers. But Nomi actually matches each phone with an
individual in order to create a profile of them. The profile
features information like recent visits, purchase history, and
Web browsing history.

Nomi's analytics are anonymous unless a customer opts-in and
chooses to identify himself as part of an existing loyalty
program.

But Nomi and Walkbase are just two of many companies trying to
help retailers learn more about their customers and better
compete against e-commerce giants like Amazon.

Disclosure: Jeff Bezos is an investor in Business Insider through his
personal investment company Bezos Expeditions.